Bolt-anchor.



H. W. PLEISTEH.

BOLT ANCHOR.

APPLICATloN FILED SEPT. 18, 1911.

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WITNESS.-

Patented May 28, i918.

HENRY vv. PLEIsTER, or wEs'iEiELn, NEW JERSEY, AssieNoR To HENRY RNEWHAILL."

BOLT-ANGHR.

insinua.

specification of Letters Patent. patentar MEW gg; 19M;

Original application led September 20, 1916, Serial No. 121,105. Divided and this application filed September ii A. i 18,1912'.A Seria1No.191,919. d j l.

To all-'whomz't may/concerm l `jBejit lznown that I, HENRY W. PLEisfrEn, acitizen of the lUnited States,` residing at Westfield, inthe county of Union f and State v ofNew Jersey,liave inventedcertain new'` and useful Improvements in Bolt-Anchors,

Minore particularly to a bolt anchor which has.r afgreat holding capacity and yet4 one which will not cracky awall, a partition,` a block 'of marble, stone or any other material in which it may be desired to use my bolt anchor. i i i t p .The 'common form of bolt anchors are expanded byhaving the expanding member,`

the screw or bolt, moved down an inclined surface which extends r approximately from one end'to'the other, and which reaches its .l .this Well 01? 'partities nearest approach to the axis of the bolt anchor at the end which isfarthest embedded in the wall, block or other material. This causes the maximum expansiontol be at the very'end of the `bolt anchor. rIhis makes4 it.. impossible touse the ordinary commonw form'jof expansion bolt Yin many locations.

My expansion bolt removes the point of maximum expansion from theend of the .bolt anchor and insures a gradually lessen-` ing grip yand wedging action from that point,

to the endfof the bolt anchor.

My invention further. `relates to certain details of construction which will be dei i L scribed in the specification .and pointed out in the claims.

I haveshown in the accompanying drawingsr several illustrative 4embodiments of my invention but 0i course. it is to be understoodthat my invention is not to be confined simply to the forms illustrated. In these drawings the saine reference numerals refer to similar parts.

Y Figure lis a side elevation partly in vertical section. of atwo part lag shield enibodying my invention.

Fig. 21is a longitudinal vertical section'of the two part'lag shieldshownin Fig. 1 ex-` panded and mounted in ,a comparatively Fig.' 3 is a vertical section of a one lag shield embodying my invention.` i

Fig. 4 is avertical section of the one part lag shield of Fig. 8, mounted in a compara? tively thin block of marble, stone or similar material, the work supported being also shown in section Y l Inthe illustrative embodiment of my in- -vention illustrated in Figs. 1 and 2, 1 is a bolt anchor formed as a two part lag shield having complementary portions 2 and 3 and lugs 4.-. The axial bore 5 tapers-at 6 from fortexainple to the point.7, and from this point the axial bore `has a yreverse taper 9 f near "the large diameter at the entrance for the screw to a point intermediate its ends, as i to the large diameter atthe inner end 8 of stresses will recede `or lessen.`

It is well known that in vthin masonry vWalls or thin partitions 11, which have the strength to support thework 12 of a given weight, that it is impossible to use bolt an` chors satisfactorily because the wall or pan` tition 11 is relatively so thin that their use willcrack or destroy the surface 13 of the* wall or partition thereby giving an unsightly i appearance to the wall, it not actually re-` quiring the services of a mason `or to touchiitV up or repair By my i invention I` avoi plasterer d the cracking, or.

marring or vbreaking of the, wall or supp`0rt` 11 by removing `the maximum strain` and wedging stresses romthe points 14S, 14;,to a'` point removed from the end 8er the bolt t anchor and farenough away `from the sur-` face 13 so as tobring the point of maximum expansionwell within the body of the wall.

or 'partition 11.

To make theaction more delicate and Jte insure that no possible excessive strain shall be caused to be exerted near the endS of thebolt anchor, I provide the bolt anchor with one or more weakening portions 1,5. v

These weakening portions may be formed in any manner, `preferably by casting deep val-`- leys;16, 16 adjacent to the point 7 7 In the operation of my invention, Fig. the hole 17 yis formed in the wall or partition ileaving a comparatively thin portion 18.

i: The [bolt .anchor 1.l then inserted andthe very end 8 of the bolt anchor no such strains' will be exerted which would cause the fracture, crumbling or marring of the face 13 of the wall or support.

When the lag screw 21 passes the point 7, 7 4theweakening portion 15, 15 will, permit ,thel ends 22, 22 of the complementary sections 2 and 3 to move slightly with relation to the outer portion of the members. 2 and 3 and tend to cause the two sides Aof the valleysl, 16 to move apart or open, Fig. 2, should by any circumstances any considerable strain be exerted on the portions 22, 22

which'might have a tendency to crack or in-` jure the surface 13 ofthe wall or partition, block or any other support.

I havealso shown my invention, in Figs. 3 and 4, embodied vin a 4one partl lag shield 23. This lag` "shield is provided with an open throat 24,'one or more lugs 25, 25 and open side vr26, an inclined surface 27 reaching its nearestjapproachto the axis of the shield at the point 28 and from that point receding to the end 2.9 of the bolt anchor forming an oppositely inclined or flaring.surfacev30.v This one part .bolt anchor I provide with a weakening'portion 31 adjacent to the point 28.

This weakening portion may be formed in various ways. Preferably I form 1t by cast- 'ing a deep valley 32 which can be done at the same timefthat the article itself is cast.

n I, preferably also provide the bolt anchor with screwthreads 33, 33 which are also preferably'cast in the article.

In using this one part lag shield it is put in the h ole 34, in a thin wall or partition 35 Fig. 4, and a lag screw 36 holds the work 37 to the face 38 of the wall or partition 35 by engaging with the inclined surface 27 and the flaring surface 30, as well as directly with'the surface 39 of the' hole 34 where it will' cut orl scrapefcmale serewthreads or grooves into the body of the wall or partition 35. f y

The maximum expansion will be substantially at the point 40 and from that point will decrease or lessen to the end 29 of the shield. The weakening portion 31 insures that no possible excessive strain shall 'be caused tobe exerted near the end 29 of the bolt anchor. l/Vhen the lag screw 36 passes the vpoint 28 kthe weakening portion 31 will permit theendportion 41 to move slightly with/relation to the other por-v tion of the lag shield and will tend to cause the two sides of the4 valley 32 to move apart or open should by any circumstances any considerable strain be exerted uponvthe portion 41 which might have a tendency to crack or injure the surface 42 of the wall or partition or block or any other support 35.

y I In all the figures of the drawing the inclined flaring surfaces, as well as the action of the weakening portion, are somewhat exaggerated for the purposes of clearer illustration.

It is apparent that different thicknesses of work 12 or 37 can be held by the same bolt anchor without the lag screw 21 or 2G bindl ing before it has snugly secured the work to lappended claims.

VVhat'I claim as my invention and desire to secure by Letters Patent is:-

1. An article of manufacture comprising a bolt anchor provided with a double inclined screw engaging surface and with means to further insurethatthe maximum strains will not be transmitted to the support by the end of the bolt anchor.

2. In a bolt anchor the combination of an expansible member having` an inclined expanding surfaceA reaching its nearest approach to the axis of the anchor between the ends of said anchor and from that point reversely inclined to form a flaring surface, said bolt anchor being provided with a weakening portion, and an expanding niember adapted to engage with bothof said inclined and flaring surfaces.

3. In a bolt anchor the combination of a two part bolt anchor having an axial bore diminishing in diameter to a point intermediate its ends and from that point increasing in diameter as it advances toward the other end of the anchor, said bolt anchor being provided with one or more weakening portions, and an expanding member adapted to engage with both of said inclined and flaring surfaces.

4. In a bolt anchor the combination of a bolt anchor member having an inner expanding surface inclined from near one end to a point intermediate the ends of the anchor lmember and from that point reversely inclined to form a Haring surface, said bolt anchor member being provided with a weakening portion, andan expanding member adapted to engage with. both the inclined and flaring surfaces.

double inclined screw-threaded surface to eo- 1,267,902 lat operate directly with a lag screw, said lag body formed of comparatively rigid mateshield being provided with a iransverse rial, a double inclined screw engaging surweakening portion and a lag screw. face provided with screw threads, a weaken- 6. In a lag shield the combination of a ing portion in the body of the lag shield, l5

5 double inclined screw-threaded surface to and a lag screw coperating directly with oprraiif llirectly wihda la' screw, said the screwthreads of the inclined surfaces.

ag siie eing provi e wit a transverse y weakening portion adjacent to the nearest HENRY W PLEISTER' approach of the inclined surfaces to the axis lrVitnesses:

10 of the lag shield, and a lag screw. MARY R. RYAN,

7. In a lag shield the combination of a ELIZABETH J. Ro'rH.

Copies-of this patent may be obtained for ve centseach, by addressing the Commissioner of Patents, Washington, JD. C. 

